One sub, a two channel system ,one HT reciever ??

My equipment is Kef 104 /2's (with a Kef Kube external line level cross over currently not being used)
Audio Research LS 15
Classe Ca 2200 Power amp.
Yamaha 650 HT reciever.
Velodyne DLS-3750R sub
Levinson transport and Sonic Fronteirs DAC

The Velodyne sub has a variable cross over. Which is now set to off because the HT Reciver is managing the cross over point for HT material.

The reciever has a lfe output which I am using now for HT.

In two channel mode... I just switch inputs on the LS15 and leave the HT equpment off.

So, from what I understand I could do this.

I set the yamaha to large mains and No sub.
Ditch the LFE output to LFE line level input.
connect the sub by going from the power amp to the speaker input left and right of the sub and then from the speaker outputs to the KEF 104's. Then set the cross over on the sub to 120 Hz. Then run the reciever's auto calibration with the main LR channel set to 12 oclock on the volume control. This calibrates all of the surround and .1 channels.

This way I get the benfit of using the sub for music with the bass limited kef's and keep the LFE info from HT material going to the sub as well using the yamaha's processor.

Am I off base here?
Thanks for the reply's

The idea behind not running the signal through a crossover is that it represents an additional degradation of the signal before it has been amplified, a degradation here can never be recovered. The crossover inside speakers represent a division of frequencies of an ALREADY AMPLIFIED signal and has far less effect on the sound. I am unfamiliar with multichannel systems and so don't understand the purpose of setting the crossover at 120hz but in operation no sub should EVER be set this high. Anything operating in that range is not a sub but a woofer. I run my subs as low as possible, I never have the sub crossover set above 40hz. In this way the output of the sub is nondirectional and it supplements the bass of the main speakers instead of interfering with it. Again I am writing from the perspective of 2 channel sound and of someone who uses subs with response below 20hz. The Nelson Reed was specified to do 120db at 20hz and extend to 16hz. The REL and HSU will go almost as low but not nearly as loud; they don't have 8 12" Volt drivers as the Nelson Reed.

I am currently running Spendor SP-1/2s with a REL stadium 11 sub. I am using the speaker level inputs to the sub rather than the line level which would allow me to roll off the bass. Why. First, this is what REL recommends. Second , I have never had an active crossover I couldn't hear. Such may exist but they would be very expensive. A custom passive crossover would be the way I would go if I was inclined to use one. For me the critical factor it that running the main speakers full range is what they were designed for. Rolling off their bass may enable them to play louder but when I have tried it I found the benefits mostly theoretical and the drawbacks obvious. BUT, if I have learned anything in 45 wears in audio it is we all hear differently and listen to different things in music so it a personal choice.